INTRODUCTION. li 



state that there are no difficulties for the botanical student to overcome ; 

 on the contrary, there is no science which demands more minute accuracy 

 of observation, more patient research, or a more constant exercise of the 

 reasoning faculties, than that of Botany. But no subject of human in- 

 quiry can be pursued loosely and usefully at the same time ; for we may 

 rest assured, that that which can be studied superficially is little deserving 

 of being studied at all. 



It may perhaps be urged, that the Natural System is still in so unsettled 

 a state, that botanists disagree among themselves about the limits and rela- 

 tive position of the orders; an argument to which some weight undoubt- 

 edly attaches. But, at the same time, it must be remarked, that all sciences 

 of observation proceed towards a settled state by slow degrees ; that Botany 

 is one upon which there is at least as much to learn as is at present known ; 

 and that the differences of opinion, just alluded to, affect the orders themselves 

 but little, and the principles of the science not at all, but apply rather to 

 the particular series in which the orders should stand with relation to each 

 other — a point which is not likely to be settled at present, and which is of 

 very little importance for any useful purpose. 



The last kind of difficulty, and the only one of which I admit the force, 

 is the want of an introductory work upon the subject; and this, I presume 

 to hope, will be diminished by the appearance of the present publication. 



The principle upon which I understand the Natural System of Botany 

 to be founded is, that the affinities of plants may be determined by a con- 

 sideration of all the points of resemblance between their various parts, 

 properties, and qualities ; and that thence an arrangement may be deduced 

 in which those species will be placed next each other which have the 

 greatest degree of relationship ; and that consequently the quality or struc- 

 ture of an imperfectly known plant may be determined by those of another 

 which is well known. Hence arises its superiority over arbitrary or arti- 

 ficial systems, such as that of Linnaeus, in which there is no combination 

 of ideas, but which are mere collections of isolated facts, not having any 

 distinct relation to each other. 



This is the only intelligible meaning that can be attached to the term 

 Natural System, of which Nature herself, who creates species only, knows 

 nothing. It is absurd to suppose that our genera, orders, classes, and the 

 like, are more than mere contrivances to facilitate the arrangement of our 

 ideas with regard to species. A genus, oider, or class, is therefore called 

 natural, not because it exists in Nature, but because it comprehends species 

 naturally resembling such other more than they resemble any thing 

 else. 



The advantages of such a system, in applying Botany to useful pur- 

 poses, are immense, especially to medical men, with whose profession the 

 science has always been identified. A knowledge of the properties of one 

 plant is a guide to the practitioner, which enables him to substitute some 

 other with confidence, which is naturally allied to it ; and physicians, on 

 foreign stations, may direct their inquiries, not empirically, but upon fixed 

 principles, into the qualities of the medicinal plants which nature has pro- 

 vided in every region for the alleviation of the maladies peculiar to it. To 

 horticulturists it is not less important : the propagation or cultivation of one 

 plant is usually applicable to all its kindred ; the habits of one species in an 

 order will often be those of the rest ; many a gardener might have escaped 



